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Veterinary Research Nov 2022Streptococcus suis is a zoonotic agent that causes sepsis and meningitis in pigs and humans. S. suis infections are responsible for large economic losses in pig... (Review)
Review
Streptococcus suis is a zoonotic agent that causes sepsis and meningitis in pigs and humans. S. suis infections are responsible for large economic losses in pig production. The lack of effective vaccines to prevent the disease has promoted the extensive use of antibiotics worldwide. This has been followed by the emergence of resistance against different classes of antibiotics. The rates of resistance to tetracyclines, lincosamides, and macrolides are extremely high, and resistance has spread worldwide. The genetic origin of S. suis resistance is multiple and includes the production of target-modifying and antibiotic-inactivating enzymes and mutations in antibiotic targets. S. suis genomes contain traits of horizontal gene transfer. Many mobile genetic elements carry a variety of genes that confer resistance to antibiotics as well as genes for autonomous DNA transfer and, thus, S. suis can rapidly acquire multiresistance. In addition, S. suis forms microcolonies on host tissues, which are associations of microorganisms that generate tolerance to antibiotics through a variety of mechanisms and favor the exchange of genetic material. Thus, alternatives to currently used antibiotics are highly demanded. A deep understanding of the mechanisms by which S. suis becomes resistant or tolerant to antibiotics may help to develop novel molecules or combinations of antimicrobials to fight these infections. Meanwhile, phage therapy and vaccination are promising alternative strategies, which could alleviate disease pressure and, thereby, antibiotic use.
Topics: Humans; Swine; Animals; Streptococcus suis; Streptococcal Infections; Anti-Bacterial Agents; Macrolides; Swine Diseases
PubMed: 36371221
DOI: 10.1186/s13567-022-01111-3 -
Pathogens (Basel, Switzerland) Aug 2020is considered among the top bacterial pathogens leading to important economic losses to the swine industry, with the incidence of disease increasing as the prophylactic...
is considered among the top bacterial pathogens leading to important economic losses to the swine industry, with the incidence of disease increasing as the prophylactic use of antimicrobial is being vanished worldwide. is also a zoonotic agent afflicting people in close contact with infected pigs or pork meat. Besides, in some Asian countries, it is considered a major public health concern for the general population as well. Antimicrobial resistance is one of the most important global health challenges, and in the absence of preventive measures (such as effective vaccines), remains a risk for increased antimicrobial resistance and transmission of resistance genes to other bacteria beyond the host animal species. The studies in this Special Issue have evidenced the importance of swine population demographics and management on disease control, progress in molecular tools to better understand the epidemiology of infections in swine and humans, and the mechanisms involved in different aspects of the immuno-pathogenesis of the disease. The importance of reducing the prophylactic use of antimicrobials in livestock productions and the development of alternative control measures, including vaccination, are herein discussed.
PubMed: 32867188
DOI: 10.3390/pathogens9090707 -
Nature Communications Apr 2023Synthesis of capsular polysaccharide (CPS), an important virulence factor of pathogenic bacteria, is modulated by the CpsBCD phosphoregulatory system in Streptococcus....
Synthesis of capsular polysaccharide (CPS), an important virulence factor of pathogenic bacteria, is modulated by the CpsBCD phosphoregulatory system in Streptococcus. Serine/threonine kinases (STKs, e.g. Stk1) can also regulate CPS synthesis, but the underlying mechanisms are unclear. Here, we identify a protein (CcpS) that is phosphorylated by Stk1 and modulates the activity of phosphatase CpsB in Streptococcus suis, thus linking Stk1 to CPS synthesis. The crystal structure of CcpS shows an intrinsically disordered region at its N-terminus, including two threonine residues that are phosphorylated by Stk1. The activity of phosphatase CpsB is inhibited when bound to non-phosphorylated CcpS. Thus, CcpS modulates the activity of phosphatase CpsB thereby altering CpsD phosphorylation, which in turn modulates the expression of the Wzx-Wzy pathway and thus CPS production.
Topics: Phosphorylation; Streptococcus suis; Polysaccharides, Bacterial; Protein Serine-Threonine Kinases; Phosphoric Monoester Hydrolases; Bacterial Capsules
PubMed: 37120581
DOI: 10.1038/s41467-023-38210-4 -
Frontiers in Microbiology 2020is a zoonotic bacterial swine pathogen causing substantial economic and health burdens to the pork industry. Mechanisms used by to colonize and cause disease remain...
is a zoonotic bacterial swine pathogen causing substantial economic and health burdens to the pork industry. Mechanisms used by to colonize and cause disease remain unknown and vaccines and/or intervention strategies currently do not exist. Studies addressing virulence mechanisms used by have been complicated because different isolates can cause a spectrum of disease outcomes ranging from lethal systemic disease to asymptomatic carriage. The objectives of this study were to evaluate the virulence capacity of nine United States isolates following intranasal challenge in swine and then perform comparative genomic analyses to identify genomic attributes associated with swine-virulent phenotypes. No correlation was found between the capacity to cause disease in swine and the functional characteristics of genome size, serotype, sequence type (ST), or virulence-associated phenotypes. A search for orthologs found in highly virulent isolates and not found in non-virulent isolates revealed numerous predicted protein coding sequences specific to each category. While none of these predicted protein coding sequences have been previously characterized as potential virulence factors, this analysis does provide a reliable one-to-one assignment of specific genes of interest that could prove useful in future allelic replacement and/or functional genomic studies. Collectively, this report provides a framework for future allelic replacement and/or functional genomic studies investigating genetic characteristics underlying the spectrum of disease outcomes caused by isolates.
PubMed: 33574803
DOI: 10.3389/fmicb.2020.620843 -
Pathogens (Basel, Switzerland) Jan 2020Diseases caused by are a significant economic and welfare concern in pigs as well as in humans. Several molecular methods have been applied to investigate S. suis... (Review)
Review
Diseases caused by are a significant economic and welfare concern in pigs as well as in humans. Several molecular methods have been applied to investigate S. suis strain diversity and identify phylogenetic groups. Multilocus sequence typing (MLST), commonly used to differentiate between strains, has been instrumental in identifying that the species is genetically highly diverse. Recent advances in whole-genome analysis have resulted in schemes permitting the classification of S. suis populations as pathogenic or non-pathogenic, or disease-associated or non-disease associated. Here, we review these and other molecular approaches that can be used for surveillance, outbreak tracking, preventative health management, effective treatment and control, as well as vaccine development, including PCR based-assays that are easy to apply in modest diagnostic settings and which allow for the rapid screening of a large number of isolates at relatively low cost, granting the identification of several major clonal complexes of the population.
PubMed: 32012668
DOI: 10.3390/pathogens9020081 -
Microorganisms Nov 2021is a swine pathogen and zoonotic agent responsible for economic losses to the porcine industry. Infected animals may develop meningitis, arthritis, endocarditis, sepsis... (Review)
Review
is a swine pathogen and zoonotic agent responsible for economic losses to the porcine industry. Infected animals may develop meningitis, arthritis, endocarditis, sepsis and/or sudden death. The pathogenesis of the infection implies that bacteria breach mucosal host barriers and reach the bloodstream, where they escape immune-surveillance mechanisms and spread throughout the organism. The clinical manifestations are mainly the consequence of an exacerbated inflammation, defined by an exaggerated production of cytokines and recruitment of immune cells. Among them, neutrophils arrive first in contact with the pathogens to combat the infection. Neutrophils initiate and maintain inflammation, by producing cytokines and deploying their arsenal of antimicrobial mechanisms. Furthermore, neutrophilic leukocytosis characterizes infection, and lesions of infected subjects contain a large number of neutrophils. Therefore, this cell type may play a role in host defense and/or in the exacerbated inflammation. Nevertheless, a limited number of studies addressed the role or functions of neutrophils in the context of infection. In this review, we will explore the literature about and neutrophils, from their interaction at a cellular level, to the roles and behaviors of neutrophils in the infected host in vivo.
PubMed: 34835517
DOI: 10.3390/microorganisms9112392 -
Veterinary Sciences Sep 2020causes severe infections in both swine and humans, making it a serious threat to the swine industry and public health. Insight into the physiology and pathogenesis of... (Review)
Review
causes severe infections in both swine and humans, making it a serious threat to the swine industry and public health. Insight into the physiology and pathogenesis of undoubtedly contributes to the control of its infection. During the infection process, a wide variety of virulence factors enable to colonize, invade, and spread in the host, thus causing localized infections and/or systemic diseases. Enzymes catalyze almost all aspects of metabolism in living organisms. Numerous enzymes have been characterized in extensive detail in , and have shown to be involved in the pathogenesis and/or physiology of this pathogen. In this review, we describe the progress in the study of some representative enzymes in , such as ATPases, immunoglobulin-degrading enzymes, and eukaryote-like serine/threonine kinase and phosphatase, and we highlight the important role of various enzymes in the physiology and pathogenesis of this pathogen. The controversies about the current understanding of certain enzymes are also discussed here. Additionally, we provide suggestions about future directions in the study of enzymes in .
PubMed: 32977655
DOI: 10.3390/vetsci7040143 -
Microbiology Spectrum Feb 2022To investigate the presence and location of (T) in clinical Streptococcus suis isolates and explore the transmission ability and fitness cost of (T)-carrying mobile...
To investigate the presence and location of (T) in clinical Streptococcus suis isolates and explore the transmission ability and fitness cost of (T)-carrying mobile genetic elements among S. suis isolates, MICs were determined by broth microdilution. The presence of (T) in S. suis was detected by PCR. The genetic environment of (T) in S. suis was explored by whole-genome sequencing (WGS) analysis. Intraspecies and interspecies transmission were examined by electrotransformation. The fitness cost associated with the carriage of an (T)-harboring plasmid or an integrative and conjugative element (ICE) was examined by competition experiments. Of 237 nonduplicate strains, (T) was detected in 2 S. suis strains (SC262-ST954 and SC117-ST1314), with its location on a 5,125-bp plasmid in S. suis SC262 and on a 64,013-bp ICESC117 in S. suis SC117, respectively. Both the (T)-carrying plasmid pSC262 and the ICESC117 were transmissible by transformation. Plasmid pSC262 can replicate and express macrolide-lincosamide resistance in heterologous hosts, including S. aureus and S. pneumoniae. Both the (T)-carrying plasmid and the ICE posed a fitness cost to the host S. suis isolate. To the best of our knowledge, this is the first report of the macrolide-lincosamide-streptogramin B resistance gene (T) in S. suis. Its location on a plasmid or an ICE will aid in its transmission. The low detection rate of (T) gene among the S. suis population might be due to the fitness cost of the (T)-carrying plasmid and ICE. Macrolide and lincosamide resistance due to the presence of (T) have posed a challenge for the treatment of Gram-positive pathogens. Although the low detection rate of (T) gene among the S. suis population due to the fitness cost of the (T)-carrying plasmid and ICE, the presence of (T) in S. suis and its potential transmission to other Gram-positive pathogens will be of important significance.
Topics: Anti-Bacterial Agents; Bacterial Proteins; Drug Resistance, Bacterial; Gene Transfer, Horizontal; Humans; Lincosamides; Macrolides; Microbial Sensitivity Tests; Staphylococcus aureus; Streptococcal Infections; Streptococcus pneumoniae; Streptococcus suis
PubMed: 35019703
DOI: 10.1128/spectrum.01657-21 -
Frontiers in Medicine 2021is a human zoonotic pathogen of occupational origin, with infection acquired through contact with live pigs or pig meat. Pig farming is one of Catalonia's biggest...
is a human zoonotic pathogen of occupational origin, with infection acquired through contact with live pigs or pig meat. Pig farming is one of Catalonia's biggest industries and as a result this region of Spain has one of the highest density pig populations per km. The aim of our study was to describe the infections caused by occurring in that area over a 9-year period. A retrospective, multi-center study was carried out by searching records from 15 hospitals in Catalonia for the period between 2010 and 2019. Over the study period altogether nine cases of infection were identified in five hospitals, with five of these cases occurring in the 2018-2019 period. The mean age of patients was 48 ± 8.9 years and all of them were males. Five patients (55.6%) worked in pig farms. The most frequent manifestation of infection was meningitis (5 cases; 55.6%) followed by septic arthritis (3 cases; 33.3%). None of the patients died at 30 days; nonetheless, 4 developed hearing loss as a long-term complication. The most commonly identified infection was meningitis. Over 50% of the episodes occurred in the last 2 years and have affected pig farm workers. Further surveillance is needed in order to know its prevalence.
PubMed: 34957160
DOI: 10.3389/fmed.2021.792233 -
Emerging Infectious Diseases Dec 2019Streptococcus suis is an emerging agent of zoonotic bacterial meningitis in Asia. We describe the epidemiology of S. suis cases and clinical signs and microbiological...
Streptococcus suis is an emerging agent of zoonotic bacterial meningitis in Asia. We describe the epidemiology of S. suis cases and clinical signs and microbiological findings in persons with meningitis in Bali, Indonesia, using patient data and bacterial cultures of cerebrospinal fluid collected during 2014-2017. We conducted microbiological assays using the fully automatic VITEK 2 COMPACT system. We amplified and sequenced gene fragments of glutamate dehydrogenase and recombination/repair protein and conducted PCR serotyping to confirm some serotypes. Of 71 cases, 44 were confirmed as S. suis; 29 isolates were serotype 2. The average patient age was 48.1 years, and 89% of patients were male. Seventy-seven percent of patients with confirmed cases recovered without complications; 11% recovered with septic shock, 7% with deafness, and 2% with deafness and arthritis. The case-fatality rate was 11%. Awareness of S. suis infection risk must be increased in health promotion activities in Bali.
Topics: Adult; Aged; Bacterial Proteins; Biomarkers; DNA Restriction Enzymes; Female; Geography, Medical; History, 21st Century; Humans; Indonesia; Male; Meningitis, Pneumococcal; Middle Aged; Phylogeny; Polymerase Chain Reaction; Public Health Surveillance; Serotyping; Streptococcus suis; Symptom Assessment
PubMed: 31742523
DOI: 10.3201/eid2512.181709